The existing building is comprised of a double span portal framed construction with hipped roofs at the ends. The walls and roofing are clad with profiled metal sheeting with dwarf brick walls externally and 2m high block walls internally.

Due to the location on a steeply sloping site with deep fill the original building was constructed on piles with ground beams and a suspended ground floor making the structural alterations more complex.

The main structural alterations that were carried out were as follows: